Repro for openapi-generator - OpenAPI declaration with inner enum

inner_enum.yaml

openapi: 3.0.1
info:
  title: Test inner enum
  version: v1
paths: {}
components:
  schemas:
    Status:
      type: object
      properties:
        options:
          type: object
          additionalProperties:
            type: array
            items:
              type: string
              enum:
                - AB01
                - AB02
                - AB03